1. You can have another party member cast the spell.
Anyone in the party can pay the cost of the consumed material components.
Downtime: Spellcasting Services
If you finish an episode or adventure, need [sic] a spell cast, you can
spend one downtime day and pay lifestyle expenses plus the cost of the
spell to have an appropriate spell cast. Alternatively, another party
member can provide the service. Both you and the spellcaster in your
party spend one downtime day to have the spells cast. Anyone in the
party can pay the cost for consumed material components for spells
such as raise dead. If your character is raised from the dead during
the course of an adventure, he or she can continue to play and gain
rewards from that play, but the penalties imposed by the raise dead
spell apply.
DDAL Players Guide v5.1, p. 4 (bold emphasis added)
Characters with the acolyte background have additional benefits when using this option.
Acolyte Background. A character possessing the acolyte background requesting spellcasting services at a temple of their faith can request one spell per day from the Spellcasting Services table for free. The only cost paid for the spell is the base price for the consumed material component, if any is required.
Only some faiths are represented by temples large enough to provide this benefit. When playing any given adventure, the available faiths are determined by the season or region in which the adventure is set.
DDAL Dungeon Master's Guide v2.1, pp. 6-7
2. You pay for the spell yourself
(your question excludes this possibility, but I'm including it here for completeness).
Dead Character Pays for Raise Dead. If the character’s body is recoverable (it’s not missing any vital organs and is mostly whole) and the player would like the character to be returned to life, the party can take the body back to civilization and use the dead character’s funds to pay for a raise dead spell.
DDAL Dungeon Master's Guide v2.1, p. 7
3. Other party members pay for the spell.
You don't have to pay them back.
Character’s Party Pays for Raise Dead. As above, except that some or all of the 1,250 gp for the raise dead spell is paid for by the party at the end of the session. Other characters are under no obligation to spend their funds to bring back a dead party member.
DDAL Dungeon Master's Guide v2.1, p. 7
4. Faction Charity at levels 1-4
(original question excludes this possibility, but I include it here for completeness)
Note: This option is not available in Season 4 (Curse of Strahd/Barovia). There is an alternate option in use for that season.
Faction Charity. If the character is of level 1 – 4 and a member of a faction, a patron from the faction ensures that he or she receives a raise dead spell. However, any character invoking this charity forfeits all XP and rewards for that session (even those earned prior to death during that session), and cannot replay that episode or adventure with that character again. The character takes a −4 penalty to attack rolls, saving throws, and ability checks. Every time the character finishes a long rest, the penalty is reduced by 1 until it disappears. Once a character reaches 5th level, this option is no longer available.
DDAL Dungeon Master's Guide v2.1, p. 7
5. You're out of luck. Dead.
Create a New 1st-Level Character. If the dead character is unwilling or unable to exercise any of the other options, the player creates a new character. The new character does not have any items or rewards possessed by the dead character.
DDAL Dungeon Master's Guide v2.1, p. 7
6. Use DM Rewards
There is no official documentation about this process (to date), but there are community discussions which converge on this process.
- Party members deliver body to a temple that provides spellcasting services. It is assumed that gentle repose is cast by the temple clerics to preserve the body.
- Apply DM Rewards to the character's Adventure Log. Gold and XP suddenly become available to the character. Magic!
- Pay the gold and downtime day costs for the appropriate spell to return to life.